Postmastectomy lymphedema (PML) is a morbid condition occurring in patients with breast carcinoma treated with radical/modified radical mastectomy. Postmastectomy angiosarcoma (PMA) is the most common neoplasia seen in these patients. Primary malignant lymphoma arising in PML is a rare neoplasia and 3 cases have been reported until now. In this report a patient with diffuse large cell lymphoma (DLCL) arising in PML is reported and the other three cases are reviewed.